1. Field of the Invention
This invention pertains to the diagnosis and treatment of infectious bursal disease in poultry, particularly chickens. Specifically, a novel virus and monoclonal antibodies (MCAs) are identified which can be used in the diagnosis of, and prevention of, infectious bursal disease infection of a variety of types.
2. History of the Invention
In 1987, research into infectious bursal disease (IBD) viral infections that were not contained by conventional passive transfer of maternal antibodies or inoculation with a virulent strains resulted in the identification of two neutralizing antibodies, designated R63 and B69, expressed by cell lines deposited at the ATCC under Deposit Nos. 9490 and 9437, respectively, that can be used to prepare vaccines against the virus (IBDV). This work is disclosed in parent U.S. patent application Serial No. 07/061,083, filed June 12, 1987, the entire disclosure of which is incorporated herein by reference.
Subsequent testing of these MCAs identified the development of a new variant IBDV strain not neutralized by these two MCAS. A combination of neutralizing and non-neutralizing but group specific reactive antibodies can be used to identify the presence of the new strain, designated GLS. This work is fully disclosed in parent U.S. application Ser. No. 07/227,311, filed Aug. 2, 1988, the entire disclosure of which is incorporated herein, by reference.
The inventor has now developed a panel of MCAs capable of determining the presence of IBDV, the strain type or types present, and mixture of strains, if present. This panel includes, four additional MCAs which may be employed for use as a diagnostic. Three new MCAs may be used in the preparation of a IBDV vaccine.
Through processes similar to those developed in parent U.S. application Ser. No. 07/061,083, a panel of MCAs have been established which can be selectively combined to detect the presence of IBD in a poultry flock, and determine the type of strain or the mix of strains, if present. Two of these, MCA 179 and 8 are group reactive and neutralizing to all previously known IBDV. These antibodies are expressed by cell lines deposited at the ATCC, pursuant to the Budapest Treaty, under Deposit Nos. HB-10158 and HB-10174, respectively.
Additionally, the previously identified IBDV strains were reanalyzed, according to specific binding/neutralizing sites present or deleted and classified into one of three groups. Thus, xe2x80x9colderxe2x80x9d strains, all neutralized by MCA B69, were characterized as xe2x80x9cclassicxe2x80x9d. All isolates in this class were collected prior to 1985. Certain post-1985 strains apparently lost the MCA B69 neutralization site, but retained the R63 site (also present in the xe2x80x9cclassicxe2x80x9d group). These were termed the xe2x80x9cDelawarexe2x80x9d type IBDVs. The third major population of IBDV tested have also lost the R63 binding site. This is the xe2x80x9cGLSxe2x80x9d type addressed in U.S. application Ser. No. 07/227,311. MCA 179 neutralizes all three classes, as does MCA 8. All MCA sites defined can be shown to be unique in AC-ELISA and competitive binding assays.
The identification of additional monoclonal antibodies that are Delaware or GLS specific allows the determination of the specific type of mixture of IBDV present, and allows the preparation and administration of a suitably responsive vaccine. Thus, MCA 57 expressed by the cell line deposited at the ATCC under Deposit No. HB-10156, is specific for the xe2x80x9cGLSxe2x80x9d strain. MCA BK9 is specific for the xe2x80x9cDelawarexe2x80x9d type IBDV. This MCA is expressed by the cell line deposited at the ATCC and accessed by Deposit No. HB-10157.
As noted, MCA B69 specifically neutralizes xe2x80x9cclassicxe2x80x9d type viral strains. Given these three MCAs, the type of IBDV present can be identified. These infections can be prevented with vaccines prepared for the population, either generally, or in light of specific infection. General treatment vaccines can be prepared by using group specific neutralizing antibodies.